It’s difficult coming up with things to say about James Cameron’s “Terminator 2: Judgment Day” that haven’t already been said. It’s one of the few sequels that “Scream 2” does not skewer (along with “Aliens,” also directed by Cameron). “The Simpsons” have done numerous tributes to it. The movie is, quite simply, one of those landmark achievements in moviemaking. Action movies, and what the public expected from them, would be forever changed.

The story takes place seven years after “The Terminator,” and Sarah Connor (Linda Hamilton) is, well, nuts. She’s locked up in a mental institution while her son John (Edward Furlong, twice the age that his character is supposed to be) is a delinquent brat living under foster care. The machines make a second attempt to squelch the human resistance by killing John before he rises to prominence, sending a T-1000 terminator (Robert Patrick) back to kill him once and for all. The humans, meanwhile, send a reprogrammed T-800 terminator (Arnold Schwarzenegger) back to protect John. The seemingly unstoppable T-800 has its work cut out for it, though; the upgraded T-1000 is made of liquid metal, allowing it to change shape and form all sorts of stabbing weapons. John uses the T-800 to break Sarah out of the hospital and stop the defense contractor Cyberdyne Systems from creating Skynet, the AI-driven program that launches a nuclear war in the future in order to destroy mankind.

As dazzling as the special effects are in “T2” – and they are – the movie is nothing without the stunt work, which was so impressive that the late Bill Hicks declared that the only way to top it would be by using terminally ill people as stuntmen and killing them onscreen. Schwarzenegger shoots the locks off of fences inches before his motorcycle is about to slam into them. A semi truck drives off a bridge into a water duct. Patrick, in pursuit of the Connors, flies a helicopter underneath an underpass. How did he acquire the helicopter, you ask? By driving his motorcycle through the window of an office building and catching the helicopter in mid-flight, of course. Amazingly, Cameron would top this stunt three years later in “True Lies,” when he pulled Jamie Lee Curtis out of the sun roof of a limo by a helicopter right as the limo plummets into the ocean. But that makes the cycle-to-copter stunt no less impressive.

The casting of Patrick as the T-1000 is a move of sly genius. He’s considerably smaller than Schwarzenegger, of course, which adds an extra level of intrigue to their hand-to-hand combat scenes. Schwarzenegger should be able to punch right through Patrick, right? Precisely, and when he attempts to do so, Patrick morphs into a position where he can break Schwarzenegger’s arm instead. To top it off, Patrick has a look of detached menace that makes his T-1000 even creepier.

The biggest problem with “T2” is the development of Hamilton’s character. Cameron had the right idea when trying to show the ripple effect that knowing about terminators, time travel and impending nuclear holocaust would have on one’s psyche, but Hamilton’s Sarah, despite her serene narration, is completely unhinged. Watching the movie in retrospect, you understand exactly why Dr. Silberman (Earl Boen) pumps her full of Thorazine while keeping her in solitary confinement. Furlong fares better, but given that it’s his acting debut, he has his spotty moments as well. Ironically, it’s Schwarzenegger that turns in the movie’s best performance. His reading of “I need your clothes, your boots, and your motorcycle” is the movie’s most slyly funny moment.

Action movies, as a rule, have a shelf life of about six to nine months, but “Terminator 2: Judgment Day” is an action movie for the ages, worthy of Smithsonian induction. It’s big and clever, and one could argue that even Skynet would appreciate its technical skill.